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WHEN AN ENGINE OVERHEATS

Engines are designed to operate within a "normal" temperature range of about 190 to 220 degrees F. A relatively consistent operating temperature is absolutely essential for proper emissions control, good fuel economy and performance.

If the engine overheats and exceeds its normal operating range, the elevated temperatures can cause extreme stress in the cylinder head which may result in a head gasket failure. This is especially true with aluminum cylinder heads because aluminum expands about two to three times as much as cast iron when it gets hot. The difference in thermal expansion rates between an aluminum head and cast iron block combined with the added stress caused by overheating can cause the head to warp. This, in turn, may lead to a loss of clamping force in critical areas and allow the head gasket to leak.

What else can happen when an engine overheats? Coolant can boil out of the radiator and be lost. Pistons swell inside their cylinders and can scuff or seize. Valve stems can swell in their guides and also scuff or seize. This, in turn, may damage valve train components (broken rocker arms, bent pushrods, etc.) or possibly result in damaging contact between the valve head and piston if the valve sticks open. Valve lifters can also stick, possibly causing a valve to remain open a little too long. Bearings can seize. Cylinder heads can crack (especially if someone dumps cold water into the radiator in an attempt to "cool off" the engine). Combustion chambers can become so hot that a spark is no longer needed to ignite the fuel, leading to a condition known as "preignition" where the engine misfires and
runs erratically. Air/fuel mixtures are upset, and gasoline becomes less able to resist detonation. Oil thins out and is less able to protect the engine's internal components against friction and wear.

Use a straight edge and feeler gauge to check the flatness of the face of the cylinder head and block deck for warpage before replacing the head gasket.

IF AN ENGINE HAS OVERHEATED...

If a head gasket has failed as a result of severe engine overheating, both the face of the cylinder head and block deck should be checked for warpage -- and resurfaced if needed to restore flatness prior to replacing the head gasket. If the face of the head and/or block deck are not flat and are not resurfaced when the head gasket is replaced, the new head gasket will be unevenly loaded and will likely leak or fail.

Flatness can be checked by placing a straight edge on the face of the cylinder head or block, and then using a feeler gauge to check any gaps between the straight edge and head or block. If the amount of warpage exceeds the following maximum limits, the head or block is not flat enough to hold a good seal against the head gasket and should be resurfaced:

Honda Oxygen Sensor cross-reference

Subject: Honda Coolant/Anti-Freeze
Recently, several people have questioned whether the coolant (anti-freeze) sold by Honda dealers is different from the popular mass-market brands.
Honda has sent the information attached below to its dealers. While you might not expect the source to be exactly unbiased, it does provide technical information and justification for differences in their formula.

Here is the information you need to read error codes on 92-95 Civic and Del Sol (CRX). Those cars are OBD-I, so the same info should be usable for any other OBD-I Honda.

There are short and long blinks. Long blinks mean 10, and short blinks mean 1. For example, if you get "long-long-short-short-short", it means error code 23. There is a short pause between each flash (long or short) and a long pause between 2 error codes. There will always be long flashes before short flashes. So you cannot expect number 23 to be reported as "short-long-short-long-short".

1991 HONDA CIVIC SIR (EG6) - Specifications

Exhaust gases leaving your engine pass through three to four different stages before finally leaving your exhaust tip at the rear of your car. The first exhaust gases pass through an exhaust manifold or header which re-directs the exhaust from each cylinder into a single outlet or two outlets on depending on the type of engine.

Then the exhaust gases pass through a catalytic converter,through the cat-back section of the exhaust tip. Turbocharged vehicles have a turbocharger mounted to the exhaust manifold that is spun by exhaust gases. The primary purpose of the factory cat-back exhaust is to muffle the sound and redirect the exhaust to a suitable place of exit.



Upgrading to an aftermarket cat-back exhaust is a great place to start tuning your car. On turbocharged applications the manufacturers often design the exhaust to be restrictive to keep boost near stock levels. On some turbocharged applications simply changing an exhaust can free up 25-30hp. On a normally aspirated car an aftermarket exhaust becomes essential if you plan on seriously tuning your car. Headers typically add 8-10hp depending on application.



Different designs alter the torque and horsepower characteristics for different powerbands. Long primaries can boost top end power while shorter 4-2-1 designs can tune in more low to mid range torque. Depending on how flow restrictive your stock exhaust system is will determine how much power gains you get by upgrading to an aftermarket system.

Porting and Polishing should be done to your Honda to make the engine run smoother and breathe better. It involves replacing pieces to make more air flow through the engine. Thus, more readily available air to burn. Polishing makes engine run a bit smoother.



Porting & polishing are two steps or levels of the same process. The intake & exhaust runners (ports) in the head and manifolds are modified to increase flow. More flow= more power, but it's not quite as simple as that. It never is, is it? Both procedures require removal & disassembly of the cylinder head and the intake manifold. Exhaust manifolds or headers are removed as well. Polishing means exactly that- the runners are smoothed of casting flash and surface irregularities. Also the combustion chambers are smoothed and polished. The result is smoother, denser flow of gases into and out of the combustion chamber. A side benefit of polishing- small lumps & bumps in the chamber attract carbon deposits, which can superheat under load, causing detonation. Polishing removes these lumps & bumps, so your engine will be less likely to detonate. Polished chambers can allow you to run more timing advance, or more boost, or drive on cheaper gas than before the polishing job. EVERY engine taken apart to increase performance, should get a polish job. It's just good sense.

"Gasket-matching" is the next level of modification. The ports are matched to each other, using a gasket as a template. This is done to the head(s), intake, and exhaust manifold (or header) all at once. All runner transitions are made clean & smooth, from the intake, into the head, and out into the exhaust. Just like polishing, you should have EVERY engine gasket-matched if you are going so far as to take it apart to make more power. It's cheap, it works, and it's permanent (unless you wreck a head or change manifolds). If you have a die grinder, or a Dremel tool & some patience, you can do your own polishing & gasket-matching. Please do not try to do your own porting job. I don't want to hear about it.

Actual 'porting' is more elaborate, more artful, and more expensive. It is the modification of the size & shape of the intake & exhaust ports. Usually, the shop will ask you how much you want done. "A lot!" is probably NOT the right answer. The ports affect engine function like the camshafts do- they are made to function well at a specified range of RPM. Big hogged-out ports make more power at high RPM but will cause fuel puddling, stumbling, and even stalling at lower RPM. Once a port is enlarged, it cannot be 'de-ported" or made small again. For most street-driven cars (even the guys who THINK they will be running at 9000 RPM all day every day) a mild port job is all you need. The ports will be streamlined & opened up a little, giving more midrange & top end power, while keeping the ports small enough to maintain some off-idle torque.

Be wary of shortening valve guides for more flow, as this will reduce the life of the valves and the seats in the head. Be sure you can afford the long-term expense. There is a relatively new process called 'flow-porting', where the ports are enlarged by forcing a viscous, abrasive paste through the runners. This seems to work nicely, but my only experience with flow-porting leads me to recommend replacing all the valve guides AFTER the porting is done. The process can apparently open up the valve guides as well as the ports! The result was a fast Acura that smoked like a diesel.

Well here we go with another article for all of you Honda lovers out there. I am going to tell you how to install coilovers or aftermarket lowering springs in your ride. I have installed about 3 kits and all of them were on civics so if you have a different make of Honda it should follow the same guidelines but may not be exact to specs for your ride. Ok here we go, the first thing you are going to have to do is make sure you have a spring compressor if you want to be done in at least 3 hours. They sell them at the local car parts stores for around 20 bucks, they look like a bolt with two hooks on them and you just tighten the bolt once its attached to the spring and it compresses it. The kit will come with 2 of the bolt looking things and it works pretty good considering it only costs 20 bones. You can do this without a spring compressor but you have to know how to remove the drive shaft to get the strut assembly out once the spring is uncompressed.



I'm going to set this up in steps so I don't confuse anyone:

1. Loosen all of the lug nuts on the vehicle

2. Remove the 8 nuts from the strut tower assemblies (2 can be found on each tower) The top of the rear strut tower is located under the trunk carpet and may require plastic carpet clip removal to access them.

3. Jack up the entire car or just one of the wheels or just two of the wheels whichever you prefer.

4. Remove the wheel or wheels from the raised portion of the vehicle

5. Take a look at the spring assembly do you see where it is connected to on the control arm?? This is the bolt you are going to remove. You may need to hammer it out once the nut is off with a screwdriver like I do.

6. Once you have this bolt removed the strut assembly should be loose. Now comes the tricky part

7. The ones on the front are the hardest to get out because of the fork that straddles the drive shaft. You have two options here; you can loosen the strut clamping bolt on the fork and hammer on that until the fork comes loose from the strut or you can get the stock Honda scissor jack out and use it to push the fork clear of the drive shaft and then kick the strut assembly out. I usually loosen the clamp bolt and take the strut out first then I remove the fork. Whichever you prefer. The rear ones are pretty easy to get to clear of the control arm with a little elbow grease.

8. Once you have the assembly removed now would be a good time to attach the spring compressor and tighten it down to release the 300 plus pounds of force that are on the spring. DO NOT ATTEMPT TO REMOVE THE TOP HAT WITHOUT THE COMPRESSOR!!!!!! I tried this once and it shot my Allen wrench through the side of my garage. Not to mention how long it will take you to find the nut that was attached to the strut piston. Just hate to think how that would've affected my body if I would have been in the way. Anyways, once the compressor is attached remove the top hat with an Allen wrench and the proper sized open end wrench.

9. Now that you have the top hat removed we come to the point of are you installing coilovers or are you installing aftermarket lowering springs?? If you are installing coilovers go to step 10. If you are installing lowering springs go to step 11.

10. Ok so now you've got the assembly apart and your thinking "Jeez I hope I can finish this today" right? HEHE! Ok the coilover assembly should consist of the threaded collar, the adjusting "hats" that go on the threaded collar, the adjusting wrenches, the springs, and some of the kits come with three rubber grommets. Take the three grommets and slide them over the strut, next comes the collar. You want to ensure the collar slides over the top of the grommets, this prevents squeaking coming from the metal to metal contact on the strut. Next comes the "hats". Thread them onto the collar about halfway and leave them loose. The spring goes on next and finally the top hat but wait, do you see that rubber grommet that was on top of the stock spring?? Get rid of it and thread some rubber or silicone hosing over the top of the spring where it will make contact with the top hat. This will save you frustration of trying to line the big rubber washer up when you are adjusting the height of your ride before you lower it down to the ground. Now reattach the top hat to the strut and you have your complete coilover assembly ready to be reinstalled.

11. Ok so you have the springs anxiously waiting to be installed right?? Just slide the spring on, compress it, place the rubber grommet on and then bolt the top hat on, uncompress the spring and your ready to reinstall it.

12. Getting the coilover strut assembly on is a piece of cake since there is no tension on the spring. Just stick it back up in the tower and pull up on it to get it to clear the drive shaft. To get the lowered spring assembly back on you may have to use a jack or a buddy to get enough force on it to clear the drive shaft. The rear ones are pretty easy to get in regardless of the assembly. Hammer the bolt back through the control arm and tighten the nut onto it.

13. Put the strut tower nuts back on.

14. Reattach the wheels to the vehicle.

15. Check to see if you still have your fingers!

16. Remove the jack.

17. To adjust the coilovers you just have to raise or lower the hats on the collar, I can get to mine with the wheels on but some of you with the 19 inch wheels may have problems getting enough room to get your arms in to adjust them.

18. Once you get it set to the height you want it at, definitely go out and get an alignment unless of course you have big bucks for tires and enjoy how your vehicle pulls all over the road.

Article source : http://www.purehonda.com
By: Sean Fillner" HYPED1@peoplepc.com

Performance enthusiasts are always in search of more power because there's never enough. However, the correct combination of performance products can leave you satisfied. It just takes a lot of time and patience to figure out what your vehicle responds to best. First,You need an air filter, header, exhaust, throttle body, cams, adjustable cam sprockets, and ported head. To draw more power, a turbocharger, supercharger and/or NOS can be added.

If you want your car to perform better and last longer, you should do it as recommended or needed. Its just like oil, you have to take care of your engine, or it wont run good, or you will tap a valve. The valve are basically screwed on and tourqued to a certain measurement for example (8mm exhaust - 7mm intake ). The tool is a feeler gauge and it just has a bunch of different sizes or gaps you use.



It is recommended every 15k miles, or when they start to tap, trust me they will start to tap if you take it to redline all the time.